Of course this kind of thing is easier said than done. But the good news was these errors weren’t coming on high percentage missed opportunities. In large part they came from trying shots from improbable (and occasionally impossible) positions. This was in part due to the frustration of dealing with her opponent’s tendencies to hit deep, topspin moonballs, and also, the length of the rallies which often went to 10 balls or more. 

What Yulia lacked was the ability to distinguish what her real opportunities were, and when to take advantage of them. Her mind set was to play aggressively, but this sometimes prevented her from realizing exactly where she was on the court and when she was in a defensive position. 

No doubt, getting the opportunities to finish was difficult against this opponent. She rarely missed and didn’t mind pushing. But that was no excuse for trying to create opportunities where they didn’t exist.   

What Yulia desperately needed was to understand how to build points - how to work the exchanges over the course of several balls to create the opportunity to put her weapons into play.

This was true from the baseline. It was also true at the net.  She had success in a handful of points with her volleys and overheads. She also was able to counter some of her opponent’s junk with drop shots and at least one lob winner.

When she used her more varied shotmaking in this way, the percentages were  in her favor. She won more points (6) than she lost (4). But this was in less than 10% of the total number of points, and not quite enough to make a difference. 

The numbers showed she had more variety and more firepower than her opponent. If she had simply believed this more, she would have had the patience and the confidence to work the points, be patient, and eventually bring her forehand and other weapons into play. 

We could see the same exact same phenomenon in the match she lost in the national tournament. The score was the most lopsided of all the matches I charted, 6-2, 6-0. But once again, Yulia had more winners. In fact the ratio there was almost 2 to 1, 22 winners for Yulia to only 12 for her opponent! This was in a match in which she only won 2 games! 

What happened? Basically a more extreme version of the sectional match. The girl was extremely consistent, kept the ball deep, moved very well, and made fewer errors than Yulia’s opponent in the high school tournament.   

Interestingly, even though she beat Yulia so easily, her Aggressive Margin was actually negative at –2.5 per set.  It was just that Yulia’s Aggressive Margin was much more negative at –11.5 per set. 

How can you hit twice as many winners and still lose 6-2, 6-0? Again you have to look at the unforced errors.  Yulia made 37 unforced errors off the ground.

Her 14 forehand winners were offset by 21 forehand errors. She had only 3 backhand winners, but 16 backhand unforced errors. That’s 53 points she gave away.

Once again, most of these errors came from deep, defensive positions caused by Yulia’s frustration at the girl’s consistency and by her own tendency to try for the impossible. As in the first match, if she had simply cut here errors in half, the outcome might very well have been different.

As in the other match, Yulia also could have brought the variety of her game more into play. She actually won 4 of the 5 points when she was at the net. But she lacked the patience to work for the opportunities to go in more. Drop shots would have been another great way to break up this girl’s game, and to her credit, Yulia tried two in the first set. But she happened to miss them both and didn’t try another one for the rest of the match.

Interestingly, after Yulia lost, I stuck around LA for a couple of days and actually had the chance to chart one set in the final match of the tournament between 2 more highly nationally ranked kids. They played a long tie-break set. The winning player ended with an Aggressive Margin of +1, the loser an Aggressive Margin of –3. In terms of the shot making potential, Yulia was right there with these players.

The question: how to get that potential to reality? The answer lies in altering the way she practices, and also, in playing certain types of matches.

One of my biggest frustrations in observing the state of coaching is watching players repeat the same mistakes over and over again. The first step in breaking this cycle can be the information that comes from match charting.

The second step is devising competitive situations that allow a player to work on new patterns and shot combinations. It’s guaranteed that these changes won’t occur if a player simply goes from working on something on the teaching court to playing a closely contested competitive match.

In Yulia’s case she needed to play baseline practice games where she is required to hit 5 or 10 crosscourts, particularly backhands, before going for a shot.

Another game: draw an imaginary (or even a chalk) line across the court, halfway between the service line and the baseline. She can go for a winner anytime the ball lands in front of that line—but never when it lands behind.

Now she needs to visualize where that line is in her matches, then keep charting matches to see if the errors from the wrong positions stay the same or go down.

Regarding her attacking and her touch game, the key is to try these shots in matches where a few errors won’t threaten the result. For example, in a good part of her high school team season, Yulia faced players 2 or 3 levels below her.

In these matches, she had to serve and volley, on both first and second serves, whenever she was a point or more ahead on her service games. On her return games, it was the same idea, she had to hit a drop shot or an approach shot and go in on any second serve when she was a point ahead in the game. The more she made the more confident she became. Gradually a few of those points will work their way into the higher level competitive matches.

The beauty of the statistical analysis is that it makes all this so concrete for the player. It’s easy to argue with someone’s opinion, whether it’s a coach or a parent, who may observe exactly the same tendencies. But it’s hard to argue with the numbers. And if you accept and really understand the numbers, it makes the path to the next level seem clear, and maybe most important attainable. Next: How to do this charting for yourself.

For more information on John Yandell's Advanced Tennis Research Project, click here.